Fix --sdistonly behaviour (#2775)

docs/changelog/2653.bugfix.rst

@@ -0,0 +1 @@
+Fix ``--sdistonly`` behaviour.

src/tox/session/cmd/run/common.py

@@ -299,7 +299,11 @@ def _queue_and_wait(
 
             def _run(tox_env: RunToxEnv) -> ToxEnvRunResult:
                 spinner.add(tox_env.conf.name)
-                return run_one(tox_env, options.parsed.no_test, suspend_display=live is False)
+                return run_one(
+                    tox_env,
+                    options.parsed.no_test or options.parsed.package_only,
+                    suspend_display=live is False,
+                )
 
             try:
                 executor = ThreadPoolExecutor(max_workers=max_workers, thread_name_prefix="tox-driver")

src/tox/tox_env/runner.py

@@ -165,7 +165,8 @@ def _register_package_conf(self) -> bool:
 
     def _setup_pkg(self) -> None:
         self._packages = self._build_packages()
-        self._install(self._packages, RunToxEnv.__name__, "package")
+        if not self.options.package_only:
+            self._install(self._packages, RunToxEnv.__name__, "package")
         self._handle_journal_package(self.journal, self._packages)
 
     @staticmethod

tests/tox_env/test_tox_env_runner.py

@@ -0,0 +1,27 @@
+from pathlib import Path
+
+from tox.pytest import ToxProjectCreator
+
+
+def test_package_only(
+    tox_project: ToxProjectCreator,
+    demo_pkg_inline: Path,
+) -> None:
+    ini = "[testenv]\ncommands = python -c 'print('foo')'"
+    proj = tox_project(
+        {"tox.ini": ini, "pyproject.toml": (demo_pkg_inline / "pyproject.toml").read_text()},
+        base=demo_pkg_inline,
+    )
+    execute_calls = proj.patch_execute(lambda r: 0 if "install" in r.run_id else None)
+    result = proj.run("r", "--sdistonly")
+    result.assert_success()
+
+    expected_calls = [
+        (".pkg", "_optional_hooks"),
+        (".pkg", "get_requires_for_build_sdist"),
+        (".pkg", "build_wheel"),
+        (".pkg", "build_sdist"),
+        (".pkg", "_exit"),
+    ]
+    found_calls = [(i[0][0].conf.name, i[0][3].run_id) for i in execute_calls.call_args_list]
+    assert found_calls == expected_calls